Tivo S3 upgraded to 1TB via external RAID

I was disappointed to find out that the eSata port on the new S3 was not yet active. So like the Glad Press n Seal, I decided to take matters into my own hands and increase the S3 recording capacity the old fashion way. I opened up my SuSE Linux box and expand the drives via an external RAID with an enclosure developed by Sans Digital via a SATA to eSATA cable. I first tested this by taking the original 250GB hard drive and placing it in an external drive enclosure with eSATA support. The test was successful. The following is what I did.

Test

Open the S3
Pull out the hard drive and place the hard drive into eSATA enclosure
Unplug the onboard red SATA cable
Plug in 6ft SATA to eSATA cable to the onboard SATA controller (SATA end of course)
Plug eSATA end to eSATA enclosure
Power on the eSATA enclosure make sure drive is up and running before powering up S3
Then Power on S3

Then I took the Sans Digital box with five 500 GB drives and configured it for RAID 5 giving me 2TB of storage. I ran through multiple MFSTools back up and restore options including changing the swap files to different sizes but the 2TB would not work. This just kept putting me into a GSOD loop. And yes I even tried swap sizes up to 511. Then I tried the good ole straight copy method in linux (dd) and then tested the tivo with the still original 250GB image since I did not expand the MFS partition yet and this worked. S3 booted up fine. Once I expanded the recording capacity with mfsadd the S3 would then stop working again and go into the same GSOD loop. Also after I expanded the capacity, I noticed I could not run mfsinfo. This command would just take me back to a command prompt. I plugged in the Sans Digital via USB into my MAC and ran pdisk l and noticed that the MFS partitions were there and the expanded partition (/dev/sdd15) was 1.6TB. I even tried manipulating the partitions with pdisk and still it didnt work. Then I decided to recreate the RAID 5 with a smaller volume set. This time 1.5TB and ran the exact same back up / restore /dd procedures and still that didnt work either. Then I shrunk down the volume this time to 1TB and this worked the first time with out a glich.
So I am wondering maybe the S3 kernel doesnt like seeing the expanded partition beyond a certain size. Or maybe the MFSTools does not create the partitions with the correct settings and numbers beyond a certain drive size. The following was what I did.

Create RAID 5 on Sans Digital with 2TB Volume then let the volume initialize (takes about 2 hours)
Pull out original S3 hard drive and plug into linux box
Plug Sata to eSata cable into linux box and Sans Digital RAID enclosure
Boot up linux box down load mfstools
Run mfstools backup and restore from /dec/sdc (original s3 drive) to /dev/sdd (RAID)
Unplug the onboard red SATA cable
Plug in 6ft SATA to eSATA cable to the onboard SATA controller (SATA end of course)
Plug eSATA end to eSATA enclosure
Power on Sans Digital RAID wait till all drives are up and running
Power on S3

Here is the link to the S3 with 1TB upgrade and some other pictures I took during the testing.

I did have to lug the RAID enclosure back and forth from the bedroom to the computer quite a bit. I wouldn't be surprised if there was a 1TB limit. I wonder if there is a fix around that in the kernel.

So how loud in the Sans Digital enclosure with the drives in it? I really like the idea of a raid setup and the enclosure looks to have a nice form factor.

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I was very pleased with the low sound levels. During startup as the drives are being initialized you can hear the fan but after that it sounds just like a regular pc. Compared to my ReadyNAS NV+ the Sans Digital is much lower. As a product it self the Sans is a very versatile and easy to manage product. In addition to the eSata there are USB 2.0 and Firewire 800 connections. The LAN and RS232 is for management. And the RAID is true Hot Swap.

There are already some display problems when you go above 1TiB, presumably due to a few places in the code where signed integers are being used for size-in-blocks calculations. More details in this thread.

I was very pleased with the low sound levels. During startup as the drives are being initialized you can hear the fan but after that it sounds just like a regular pc. Compared to my ReadyNAS NV+ the Sans Digital is much lower. As a product it self the Sans is a very versatile and easy to manage product. In addition to the eSata there are USB 2.0 and Firewire 800 connections. The LAN and RS232 is for management. And the RAID is true Hot Swap.

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How's the performance of the S3 with the raid 5 configuration? Have your tried recording two HD streams at the same time? Just wondering if the raid 5 write performance is a factor.

Bravo, lightrunner, on your experiment. I and others have been conjecturing on the possibility of RAID 5 on the internal SATA port and your actual proof of concept efforts are much appreciated! It is especially valuable that you encountered the size limitation anomaly as mentioned in the quoted thread. I therefore intend to stay below the 1TiB problem area using a 3 drive (WD 500GB) setup in RAID 5.

My goal is to have the final result be much quieter on seeks than a single Seagate 750 (the current noisy model). The fault-tolerant feature I think is valuable on a virtual disk that large. I don't think the traditional write bottleneck of the RAID 5 configuration will even come close to manifesting with the TiVo application. The only thing I would mention about your system is that technically your cable length is out of spec for the Tivo internal SATA port (the lowest common denominator) which is 1 meter. Might never be a problem but just wanted you to be aware of that if problems develop.

Other threads to look at for those contemplating something similar are Greg_Burns ongoing effort chronicled here and another conjecture thread here.

That Sans Digital MS2UT looks identical to my CoolGear SataVault . Wonder how the two are related?

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I have noticed that many products are just rebranded items from the same manufacturer. For example, the Siig 3 drive internal RAID frame is the same as the Accusys one (just a different color). Most likely that is the same with the two models you idenitified (one true tell is that the manuals are also identical) . The OEM relationship works well for many Taiwanese companies that may have the technology down but lack marketing expertise or contacts in other countries.

Note that those two models you specified both have the magic terms "hardware RAID" and "no drivers needed" so are Tivo ready. I really like the look. I wish they made a 3 drive box like that. The one I have settled on is actually an internal RAID (designed to slip into the 5.25" bays on a PC). So, I have to kluge power to it somehow such as with a surplus PC power supply. Maybe I can keep it all out of sight.

Lightrunner's San Digital MR5CTI RAID box is particularly flexible because you don't have to fully populate it and it has hot spare capability. It is also one of best looking boxes I have seen. The only stumbling block is that it is about $1.5k for the bare enclosure. If price is no object I would go with that one because everything about it reeks of quality. I am going to try a cheaper alternative with the goal of keeping the entire RAID 5 array as close to the price of the TiVo itself as possible.

I don't think the traditional write bottleneck of the RAID 5 configuration will even come close to manifesting with the TiVo application.

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I wouldn't count on it unless we can actually test the worst case scenario. Two recordings, 1 playback, multiple MRV and TiVo2Go (if/when we get them), program guide processing, etc. TiVo may have made certain assumptions about what a typical drive can deliver, and then allocates disk bandwidths accordingly. If we dramatically change the disk behavior due to RAID5, we may run into problems.

How's the performance of the S3 with the raid 5 configuration? Have your tried recording two HD streams at the same time? Just wondering if the raid 5 write performance is a factor.

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Last night I recorded 2 HD recordings (Raiders vs Broncos and Mets vs Cardinals) while watching a HD playback of the Cowboys vs Texans that I recorded earlier. I didn't notice any slowness or any hiccups. I compared this test with the S3 that I have in my living room with the stock 250GB drive. I scheduled the same recordings and stood in the hallway and controlled both my bedroom S3 with the plasma and my living room S3 with the dlp. I also tested by re running the guided setup to see if there were any delays but there were none. Later in the evening at about midnight I recorded 2 HD shows (An Unfinished Life and Walk the Line). As I was recording both shows I brought up the TV Guide and scrolled through several revolutions of the Guide. This also produced no delays.
I am sure if one put this setup to a bench with simulated loads and the right instruments they would be able to better guage the delays if there are any. But as a standard user I was satisfied with the performance.
I am actually surprised at the few that are complaining about RAID 5. Yes depending on the small/large read /write and the stripe size you will notice a degradation in RAID 5 performance if you have a heavy write load. Its no RAID 10 (striped mirrors) but I don't think the write loads that an S3 can produce even when recording (writing) 2 shows and watching (reading) another show can introduce such performance bottle knecks that some of us are talking about. The SANS Digital supports the Native Command Queuing as well as the Western Digital RE2 drives that are populating it.

Lightrunner,
You sure have enough shoes. Nice work on the upgrade and thanks for posting the link to images.

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Yeah the wife can't live without her Jimmy Choo's, Manolo Blanick's, etc... not too mention all her hermes,bottega, chanel, louis, gucci, etc.... bags. I really think she has watched one too many episodes of Sex In The City...

Congratulations lightrunner. Like you, I'm inclined to believe that RAID-5 in a TiVo application is more that sufficient. Consider that a 1hr show requires at most about 6GB or a sustained write of approx. 1.7MB/sec. 2 streams would demand a sustained write speed of 3.4MB/sec give or take. Given most RAID-5 write speeds are at least 2x to 3x that for on the cheap side and approaching 10x that with enterprise class hardware, I doubt we're even approaching the limitations of RAID-5.

However, I'm really curious about performance in "degraded" mode, when 1 of the volumes is rebuilding (yank drive0, replace it with a new HD). Redundancy is extremely important, but in a worst case scenario of recording 2 HD streams + watching 1 stream + 1 fictitious MRV transfer, if disk0 fails, and you replace it, can it still keep up? Sure you could wait until a lower disk demand time, but let's say you do replace the disk during peak.

With a 1TB limit, I'm inclined to stick with RAID-1 from an economy stand point... but either way this was a very interesting exercise. Great job lightrunner!